What 40k novels has bE been reading to help get their imagination flowing, from an artistic point of view?

Our team has been greatly inspired by novels set in the 40k universe such as The Horus Heresy series, Gaunt’s Ghosts series, Eisenhorn series, Fear the Alien, Codex books, Path of the Eldar, Ravenor Omnibus, Priests/ Lords/ Gods of Mars, among countless others!